In 2025, when the auto industry will be required to meet a 54.5-miles-per-gallon fuel economy target that the Obama administration plans to announce today, the vehicles Americans buy may not look very different from those on the road today. But what will be under the hood is another story, industry and environmental experts say. From pick-up trucks and sport utility vehicles to hybrids and sub-compact cars, almost every vehicle sold in the US is likely to feature the kinds of advanced technology now confined to the most fuel-efficient. Article continues below Although the new standard will be a big numerical step upward, experts say, the secret to achieving it is not some huge breakthrough. Rather, the key will be applying what\'s already known or on the drawing boards to almost every vehicle, not just a relative handful. \"You have to look at a vehicle not just as one thing that will put you over the goal line but all sorts of different things that will help you,\" said Richard Truett, a Ford Motor spokesman. \"We have a headstart on that. But everyone has to do it.\" Not every truck and SUV will have to get the higher mileage. The standard will be applied to the so-called fleet average, a complex calculation of the combined fuel efficiency of all the vehicles sold by a manufacturer in a model year. That means some gas guzzlers can still be sold; they just have to be offset by a larger number of highly fuel-efficient cars. After weeks of intensive talks at the White House with regulatory agencies, automakers, the state of California and environmentalists, President Obama plans to make a speech in Washington today to outline a plan for boosting fuel economy standards beginning in 2017 and reaching a fleet-wide average of 54.5 mpg by 2025. The new requirements build on rules starting for model year 2012 that seek to push up fuel economy to 34.1 mpg by 2016. The more efficient cars and trucks are also expected to drive down the greenhouse gas emissions linked to global warming. Right now, the American fleet of passenger vehicles averages only about 27.8 mpg. Automakers and the state of California have voiced support for the 2025 plan. Trouble-shooting After a meeting at the White House on Wednesday, environmentalists also offered tentative support, adding that they need more details about closing what they say are loopholes that automakers have used in the past to avoid the most stringent targets. \"After decades of inaction, President Obama is ensuring we see significant improvements to new vehicles, and that is significant for both cutting our addiction to oil and curbing global warming,\" said Ann Mesnikoff, director of the Sierra Club\'s green transportation campaign. Skepticism about the efficacy of new mileage targets stems in part from how they are derived and applied. The conditions for testing fuel economy have only a limited similarity to real-world driving: Cars are run in a lab at a steady speed, with the air conditioner and radio turned off. Moreover, each automaker probably will have a different standard applied to it by regulators after a political concession made in 2007 to get the support of domestic automakers. That would mean General Motors, Ford and Chrysler, whose fleets are filled with big vehicles, will probably have to meet a lower average fuel economy standard, while automakers like Honda Motor and Hyundai Motor, which tilt toward smaller vehicles, will have a higher fuel-economy requirement. Companies such as Ford are focusing on improving internal combustion engines by making them smaller to boost mileage by saving weight, then outfitting them with direct fuel injection and turbochargers to give them power. At the same time, industry experts say, hybrid technology will become more widespread and cheaper. And automakers will turn to advanced materials, including carbon fiber and high-strength steel, to make cars lighter. The appeal of revised technology can be seen in Ford\'s deployment of its Eco-boost technology. The 2012 Eco-Boost Ford Explorer is expected to get 28 mpg on the highway compared with 21 mpg for the 2010 conventional version.